Shock absorbers for crutches



Dec. 30, 1969 E3.A A. CHRYSOSTOMIDES SHOCK ABSORBERS FOR`CRUTCHES FiledJune 5, 1968 FIG. 1.

If I hill STAVRO A, CHRYSGSTOMIDES BY RWM 1% ATTORNEY Dec.30, 1969 s. A.cHRYsosToMlDEs 3,486,515

SHOCK ABSORBERS FOR-'CRUTCHES Filed June s, 1968 Y 2 sheets-sheet 2 FIG.5.

` n l' INVENTOR STAVRQACHRYSOSTOMIDES 2,4171v UM/x' ATTORNEY a UnitedStates Patent O 3,486,515 SHOCK ABSORBERS FOR CRUTCHES Stavro A.Chrysostomides, Rte. 1, Box 124, Columbia, S.C. 29203Continuation-impart of application Ser. No. 640,053, May 22, 1967. Thisapplication June 3, 1968, Ser.

Int. Cl. A61h 3/ 02; A45b 9/ 04 U.S. Cl. 135-50 4 Claims ABSTRACT OF THEDISCLOSURE A variable and adjustable shock absorber for crutchescomprising in combination: a cushion tube; a piston tube adapted toreciprocate in said cushion tube; and end plug fixed in the upper end ofsaid cushion tube; spring means adapted to maintain said cushion tubeand said piston tube in a normally extended position; a piston xed tothe upper end of said piston tube; adjustment means in said cushion tubeto effect various shock absorbing characteristics between said cushiontube and said piston tube; selection knob means associated with saidadjustment means at one end, the other end of said knob means extendingthrough said end plug and externally of said cushion tube; lock-nutmeans to fix said knob means at a selected position; side rails fixedlongitudinally with respect to said cushion tube; an adjusting space oneach side of said cushion tube formed by said rails and said cushiontube; and an adjustment bar in each of said adjusting spaces to x saidabsorber to a clutch.

This application is a continuation-in-part of my copending applicationSer. No. 640505 3, tiled May 22, 1967, and now abandoned.

This invention relates to new and useful improvements in shock absorbersfor crutches.

OBJECTS It is an object of this invention to provide structure wherebyvery slight overall height variations of the crutch may be effected.

It is an object of this invention to provide structure whereby onecrutch may be used by many various invalids, each having a differentweight.

It is an object of this invention to provide structure wherebyvariations in the cushion eifect may be made while the crutch userwalks.

It is an object of this invention to provide external structure wherebythe cushion effect may be shut off entirely when the user desires toclimb stairs and then to be re-set when normally walking.

These and other objects will become obvious from the drawings in which:

DRAWINGS FIGURE 1 shows the hydraulic or -first species;

FIGURE 2 shows the pneumatic or second species;

lFIGURE 3 shows the mechanical or third species;

FIGURE 4 shows a partial cross section of the absorber tube and crutchattachment;

FIGURE 5 shows a bifurcated composite of actual crutch connections;

FIGURE 6 shows the retaining pin relationship.

FIGURE 1 FIGURE 1 discloses a cushion tube l1 and projecting therefrom afoot tube 2 adapted to partially reciprocate in cushion tube 1. Cushiontube 1 is partially closed at its upper end by an end plug 3 beingpress-fit therein. The space between the lower internal surface ofcushion tube ice 1 and the upper end of foot tube 2 where reciprocationtakes place is sealed off by means of an O-ring 4. At the upper end offoot tube 2 is situated a piston 5 which has a reduced section 6projecting into the end of foot tube 2 and which piston 5 further haspiston rings 7. The internal space of foot tube 2 further provides for acoil spring 8 which at its upper end bears against guide pin 9 which, inturn abuts against a resilient recoil stop 11. Guide pin 9 extendsthrough guide groove 10 in the wall of piston tube 2 and into a bore inthe wall of cushion tube 1 so that guide pin 9 is motionless withrespect t-o piston tube 2 and that under the renitent pressure of coilspring V8 the cushion tube 1 and the piston tube 2 are in a normallyextended relationship. At the bottom of piston tube 2 is a tip plug 12held therein by means of pin 13. A neoprene dust cover '15 adapted tobreathe and having convolutions thereon fits around the end of pistontube 2, over the end of cushion tube 1, over collar 16, and under ringclamp 17. Over the end of the piston tube 2, tip plug 12, and dust cover15 fits the usual rubber tip 14. In the inside of cushion tube 1 atabout the midway point is fixed a valve adjusting means 18 comprising aninlet port 21 which connects oil compression chamber 38 to the oilreserve chamber 28. The ow of oil or any suitable liquid fromcompression chamber 38 to reserve chamber 28 is effectedv by theinfluence of piston tube 2 being under the pressure of the walking stepand is controlled by the needle 33 selectively restricting itscomplementary counter bore 22. The oil reserve chamber 28 is notentirely full of oil and therefore has a certain amount of air containedtherein, which air must be provided with an intake port 29 which is openon the released step of the crutch and which port 29 is closed on thewalk step or compressi-on stroke by means of a neoprene ball 30 which isheld in intake port 29 in a closed position by means of coil spring 31,which, in turn, is retained by a bored set screw held in place bythreads 32. This valve means allows air intake and prevents air lock inthe reserve chamber thereby increasing the recoil action. The expansionof the air under cornpression in oil reserve chamber 28 and the recoilof spring 8 together effect a compression suction situation which causesthe oil in reserve chamber 28 to return to the oil compression chamber38 through return port 27. This compression-suction inter-relationshipcauses a dampening of the overall cushion effect. Needle 33 is actuatedby turning selection knob 36 which is externally of the cushion tube 1and extends upwardly to allow the crutch user to determine and adjustthe cushion effect while he walks. This adjustment is selected and setby means of the needle valve stem 34 having threads 35 at the pointwhere it extends through end plug 3 and can be locked in place bytightening the knurled lock nut 37. AnhO-ring 34A around needle valvestem 34 is to prevent) leakage. Upon release of the oil pressure as theinvalid makes a step the oil is drawn back into the compression chamber38 fro-m the oil reserve chamber through the return port 27 which isclosed only on the compression stroke by means of ball-check valve 23being disposed in a counter bore 24 which ball valve 23 is held in placeby a half moon snap spring 25 which in Aturn is retained in recess 26.Fixed longitudinally along oppositely disposed sides of cushion tube 1is the side rails 20 which provide a longitudinally extending and heightadjusting bar space 39 and abutment surface 19. (See FIGS. 4 and 5.)

FIGURE 2 FIGURE 2 discloses the second or pneumatic modification whichcomprises a cushion tube 40 Iand a piston tube 41 adapted to reciprocatetherein. The upper end of cushion tube 40 is partially closed off bymeans of an end plug 42 which has a 4breather port `4 open to theatmosphere. At the lower end of cushion tube 40, Where the piston tube41 extends outwardly therefrom, there is `an O-ring `43 which acts las asliding surface guide and further as a cleaning device and to -preventscraping. At the upper end of piston tube 41 is found a piston 44 havinga reduced section 45 extending in and fixed into the bore of piston tube41. Piston 44 has a plurality of rings 46 'which act as piston ringsnormally do and further a piston bore 48 and a ball valve 49 situated insaid piston bore 48 which ball valve 49 is held in a normally closedposition by means of coil spring 50 which, in turn, is held in place bya bored set-screw held in position by threads 67. Extendinglongitudinally of the piston tube 41 is a guide groove 52 and a guidepin 51 extending through said guide groove 52 into a bore in the wall ofthe cushion tube 40 so as to be fixed relative to cushion tube 40.Between said guide pin 51 and said piston 44 is located a recoil stopwasher 53. The cushion tube 40 and the piston tube 41 are held in anormally extended position by means of coil spring 47 bearing againstthe foot of the piston tube 41 and the guide pin 51 so as to effect thenormally extended relationship which, under the pressure of walking willcause piston tube 41 to recess into c-ushion tube `40. There is fixed inthe internal walls of cushion tube 40 a valve adjusting means 55 havinga needle valve port 56 and an associated needle 57 adapted to fit snuglyinto a complementary counter bore 69 in the top of valve adjusting means55 thereby providing a restriction for the needle valve port 56. Theneedle 57 is at the lower end of the needle valve stem 58 which extendsthrough the end plug 42 and is adjustable with respect to said end plug42 by means of threads 59. Situated lon the end of needle valve stem 58is a selection knob 60 for selectively setting needle 57 of the valveadjusting means 55. Where the selection knob 60 has been activated tothe proper setting, it can be fixed in that position by means of theknurled lock-nut 61. End plug 42 further has an end plug bore 64 throughwhich the needle valve stern 58 extends and which bore further providesan O-ring 65 surrounding said needle valve stem 58 to prevent blow-by.Extending longitudinally and oppositely disposed with respect to eachother is a pair of side rails `62 fixed to the cushion tube 40 for anabutment surface 63, later to be described. The 4abutment surface 63further provides height adjusting bar space 68. At the lower end of thepiston tube `41 is found a tip plug 66 over which can be provided theusual rubber tip.

FIGURE 3 FIGURE 3 shows the mechanical species of the inventioncomprising a cushion tube 70 and a piston tube 71 adapted to reciprocatetherein. One upper end of cushion tube 70 is partially closed by meansof an end plug 72. At the top end of piston tube 71 is situated a piston73 having O-rings 74 thereon. Above the piston 73 is located compressionair space 76 and above the compression space 76 is found an adjustingmeans 78 having a plurality of O-rings 79 thereon to engage the internalwall of cushion tube 70. Compression air space 76 is additionallyoccupied by coil spring 75 which keeps cushion tube 70 and piston tube71 in a normally extended position. The resistance of spring 75 isdetermined by raising or lowering adjusting means 78 by turningselection knob 81 which acts through threaded stem 80, freely rotatingstem 82 and ball bearing `83 to set the longitudinal position ofadjusting means 78, which, when determined, can be fixed by tighteningup the knurled locknut '86 against the neoprene washer 96 and therebythe end plug 72. Above the adjusting means 78 is breather air space 84and la breather port 85 in the wall of cushion tube 70. In thecompression air space 75 is a breather port 77. Where the piston tube 71extends from the cushion tube 70 there is situated an O-ring 88 whichacts as a seal and Wiper. In the wall surface of piston tube 71 there is:a longitudinally extending guide groove 89 having a guide pin 91extending therethrough fand into a hole in the wall of cushion tube 70whereby the piston tube, under pressure, will rise the distance of theguide groove 89. A recoil stop in the form of -a -Washer is provided tomake the recoil impact smoother. Side rails 92 are provided tofacilitate the attaching of the shock absorber to a crutch by ymeans ofan abutment surface 93 and the height adjustment space 95. There isfur-ther provided a tip plug 94 over which the usual rubber tip isforced.

FIGURE 4 FIGURE 4 shows yan isometric view of the cushion tubes 1, 40,70, the side rails 20, 62, 92, the associated abutment surfaces 19, 63,93 and the longitudinally extending groove formed thereby and the height`adjustment bar 101. Extending through the adjustment bar 101 is bolt102 and wing nut 103 fastening means all f-or adjustably fixing theshock absorber to a crutch.

FIGURE 5 FIGURE 5 discloses la divided composite of a cross sectionalview of the structure necessary to fix the shock absorber tube to thepresent crutch on the left of the center line and to a metallic crutchon the right of the center line. There is shown the cushion tube 1, 40,70, the side rails 20, 62, 92, the abutment surfaces 19, 63, 93 and theadjusting bar spaces 39, 68, 95, and the adjusting bar 101. The shockabsorber is adjustably fixed to wood crutch 106 by means of bolt 102 andWing nut 103. The Shock absorber is adjustably fixed to the metalliccrutch form 105 by means of screw 104 and adjusting bar 101.

FIGURE 6 FIGURE 6 shows an enlarged View of the relationship of theguide pin 9, 51, 91 having an assembly bore 9A therein to receive a toolto facilitate the assembly thereof through a bore in the wall of cushiontube 1, 40, 70 and the guide groove 10, 52, 89 in the wall of pistontube 2, 41, 71. The piston tube 2, 41, 71 houses the coil spring 8, 47which coil spring 8, 47 Ibears against the guide pin 9, 51, 91 to keepthe guide pin 9, 51, 91 abutting against the top of the bore in the wallof cushion tube 1, 40, 70 so that the shoulders of guide pin 9, 51, 91will insure that guide pin 9, 51, 91, under constant pressure, will beretained in place. The reduced section 6, 45, 73 of the piston thatrecesses into the piston tube 2, 41, 71 rests on the top of a resilientrecoil stop 11, 53, 90 and the guide pin 9, 51, 91, under pressure,bears against the bottom of the recoil stop 11, 53, 90.

1ILlaving thus disclosed and described my invention, I c aim:

1. variable and adjustable shock absorber for crutches comprising incombination:

a cushion tube;

a piston tube closed at its lower end, the upper end adapted toreciprocate in said cushion tube;

an etrJid plug fixed in the upper end of said cushion tu e;

spring means adapted to maintain said cushion tube and said piston tubein a normally extended position;

a piston fixed to the upper end of said piston tube;

adjustment means in said cushion tube to effect various shock absorbingcharacteristics between said cushion tube and said piston tube;

selection knob means associated with said adjustment means at one end,the other end of said knob means extending externally of said cushiontube through said end plug;

lock-nut means to retain said selection knob means at a fixed position;

side rails fixed longitudinally Iwith respect to said cushion tube;

an adjusting space on each side of said cushion tube formed by saidrails and said cushion tube; and

an adjustment bar in each of said adjusting spaces adapted to x saidshock absorber to a crutch.

2. A shock absorber as in claim 1 wherein there is provided an oilcompression chamber (38) between said piston (5) and said adjustmentmeans (18); an oil reservoir chamber (28) between said adjustment meansand said end plug (3); and wherein said adjustment means is a needlevalve means (33, 22) adapted to control the flow of a hydraulic medium;and said end plug has a one-way air intake port (3).

3. A shock absorber as in claim 1 wherein said adjustment means (55) isa needle valve ('56, 57); wherein said end plug (42) is open to theatmosphere (54); wherein said piston (44) is provided with a ball valvemeans (49).

4. A shock absorber as in claim 1 wherein said selection knob means (81)effects renitent pressure in said spring means (75) 'by extending saidadjusting means (78) in a breather air space (84; said air being ventedto the atmosphere by means of a breather port (85); Isaid spring meanssituated in a compression air space (76) between said piston (73) andsaid adjusting means; said compression air space being vented to theatmosphere by means of a breather port (77).

References Cited UNITED STATES PATENTS 665,439 1/1901 Hough 135--60834,205 10/1906 Jones 13S-60 X 1,336,844 4/ 1920 Klousnitzer 135-601,464,057 8/1923 Bell 135-61 1,753,065 4/1930 Payne 135-60 2,398,5344/1946 Klousnitzer et al. 135-60 2,426,594 9/1947 Buell et al. 135-612,478,667 8/ 1949 Shellhouse et al. 13S-61 X 2,856,943 10/ 1958 Sparlin13S-49 3,304,946 2/ 1960 Lutes 135--50 FOREIGN PATENTS 880,960 10/ 1961Great Britain.

PETER M. CAUN, Primary Examiner U.S. Cl. X.R. 13S-60, 61

